This invention relates to multiple battery electric load systems, and more particularly to a device for distributing the current in a mulit-battery, multi-voltage electric load system such that the batteries in the system are protected from damage due to an imbalance of charge and the loads connected to the system are not damaged due to improper voltage.
Many electrical systems utilize separate battery banks or batteries connected in series to provide multiple voltages for starting engines, lighting and supporting electronic equipment. Examples of these systems are found on diesel powered trucks, marine equipment and off-road construction equipment. Much of this equipment uses 24 volts or higher for starting engines and running radar, and 12 volts for lights, radios and the like.
In such systems the problems exist of maintaining proper battery charge of the multiple voltages from the system charging source, typically but not limited to an alternator. Further, in the event of loss or disconnection of the negative terminals of the batteries from the common ground of the system, the potential exists for damage to equipment connected to the lower voltage of the system voltages due to the reversal of polarity in these loads.
Typical of such prior art systems is that disclosed in U.S. Pat. No. 4,479,083 in which a conventional voltage divider, such as those used to bias power amplifiers, is employed.